Victory has many colors. Photographer: Win McNamee/Getty Images
Victory has many colors. Photographer: Win McNamee/Getty Images

This may be remembered as the week that won the same-sex marriage debate.

The legislative overreach in Arizona was such an affront to Americans’ sense of equality and decency, such a vivid reminder of the days when restaurants and movie theaters could refuse to serve blacks, that proponents of Senate bill 1062 succeeded only in painting themselves as modern-day segregationists, while strengthening the public perception of marriage equality as a civil rights issue. That some opponents of same-sex marriage eventually disapproved of the bill hardly mattered. The fight over the bill was a proxy fight over the proposition that same-sex couples have a right to be treated equally under the law -- and the equal rights camp won.

They also won in Texas, where a federal judge struck down that state’s ban; in Kentucky, where a federal judge ruled that the state must immediately begin recognizing same-sex marriages performed out-of-state; and last Friday in Illinois, where a federal judge declared the state’s ban on gay marriage -- which will be lifted in June -- unconstitutional. Marriage equality proponents now hold an 8-0 record in the federal courts. In addition, this week Attorney General Eric Holder offered support for state attorneys general who refuse to defend same-sex marriage bans, declaring: “If I were attorney general in Kansas in 1953, I would not have defended a Kansas statute that put in place separate-but-equal facilities.”

There will likely be losses ahead for same-sex marriage proponents in the appellate courts, but the Rubicon has been crossed. Support for same-sex marriage has grown from 32 percent in 2003 to 53 percent in 2013, with nearly 70 percent of millennials favoring it. In addition, the eight federal judges who have struck down same-sex marriage bans were nominated by Democrats and Republicans, and they sit in different regions of the country: east (Virginia), west (California, Utah), southwest (Oklahoma, Texas), and midwest (Illinois, Kentucky and Ohio). It’s likely that some of those judges, as with so many Americans, have changed their minds on this issue over the past decade.

We have reached the point where concerns that that the Supreme Court might get ahead of public mores by ruling in favor of marriage equality can be safely put aside. This concern is most often expressed by citing Justice Ruth Bader Ginsburg’s comment last year that the Court’s decision in Roe v. Wade “seemed to have stopped the momentum that was on the side of change.” It’s debatable whether deferring a decision on abortion rights would have prevented decades of division over the issue. I’m doubtful. In any case, Roe -- which created a new right to privacy -- isn't the appropriate historical lens for viewing same-sex marriage, which is the latest in the long line of civil rights cases involving the 14th Amendment.

A better parallel, as New York University’s Pat Egan has made clear, is Loving v. Virginia, the 1967 ruling in which the Supreme Court struck down the state’s ban on interracial marriage, along with bans in 16 other states. In that case, public opinion -- in Virginia and nationally -- ran strongly against interracial marriage. Thankfully, the Supreme Court did not wait for public opinion to come around. Cases involving the equal protection clause of the 14th Amendment should not be subject to public opinion polls. The whole point of the clause is to protect minorities from having their rights trampled by majorities.

Nevertheless, it seems inevitable that public opinion will factor into the Supreme Court’s thinking when it weighs whether bans on same-sex marriage are constitutional. In fact, the cultural shift that has occurred -- reflected in public opinion polls, affirmed by eight federal courts and accelerated by events in Arizona -- may already be shifting the Court's thinking.

(Francis Barry is a member of the Bloomberg View editorial board. Follow him on Twitter.)